Belt printing apparatus for printing line of print at one time

ABSTRACT

Printing apparatus is provided in which an entire line of print is printed at one time and wherein a sheet of paper is advanced past a printing station so that a series of lines of printing can be successively printed thereon. The printing is effected in a plurality of parallel columns, with which are aligned a like number of belts on which are located the print characters. These belts are driven by one or more drums in repetitive cycles. In one embodiment, each of the belts is brought to a halt with the desired character at the printing line at the printing station and when a line of print has been thusly compiled, a single hammer unit drives the characters against a ribbon to print the line on the paper. The belts are then returned to an initial position of rest in preparation for the next succeeding cycle for the next succeeding line of print. The print hammer may be actuated from the same source of power which drives the drum or drums and there may be related to this source of power a stepping device which steps the paper through the printing station. As an alternative, a plurality of parallel belts are selectively released to be driven by a drum such that the desired characters for a line of print are brought to a printing station in unison.

United States Patent Berger et al.

[54] BELT PRINTING APPARATUS FOR PRINTING LINE OF PRINT AT ONE TIME [721 Inventors: Ralph Berger. McLean. Va.; Howard A.

Satterlee. Madeira Beach, Fla.

[73] Assignee: New England Merchants National Bank,

Boston. Mass [22] Filed: May 25, 1970 [21] Appl.No.: 40.170

Related US. Application Data [63] Continuation-impart of Ser. No. 852.697. Aug. 25.

[52] U.S.Cl. ..l01/93 C, 101/111 [51] Int. .341] 9/3B,B41j 1/20 [58] FieldolSearc ..10l/93C,1l1,l10,99.95,

[56] References Cited UNITED STATES PATENTS 2.370.735 3/1945 Keuper ..l0l/i1l X 2.204.153 6/1940 Ryan ..101I94 2.910.540 8/1959 Canepa.... .101/111 X 3 504,622 4/1970 Morrison ..l01/99 3.110.251 11/1963 Scheffel ...101/93 C 2.168.364 8/1939 Schaefer 101/336 X 3.010.387 11/1961 Deutsch... 101/93 3.139.818 7/1964 Koehn 101/93 C 2.627.807 2/1953 Buhler [Oi/93C 2.766.687 10/1956 Williams 101/99 [4 1 May 9,1972

Primary Examiner-William B. Penn Attorney-Posnack. Roberts and Cohen [57] ABSTRACT Printing apparatus is provided in which an entire line of print is printed at one time and wherein a sheet of paper is advanced past a printing station so that a series of lines of printing can be succesively printed thereon. The printing is effected in a plurality of parallel columns. with which are aligned a like number of belts on which are located the print characters. These belts are driven by one or more drums in repetitive cycles. in one embodiment, each of the belts is brought to a halt with the desired character at the printing line at the printing station and when a line of print has been thusly compiled. a single hammer unit drives the characters against a ribbon to print the line on the paper. The belts are then returned to an initial position of rest in preparation for the next succeeding cycle for the next succeeding line of print. The print hammer may be actuated from the same source of power which drives the drum or drums and there may be related to this source of power a stepping device which steps the paper through the printing station.

As an alternative, a plurality of parallel belts are selectively released to be driven by a drum such that the desired characten for a line of print are brought to a printing station in unison.

l0 Claim, 19 Drawing Figures sue/vow EL 6 TRON! c co/v TROL 86 PATENTEMM 9 m2 SHEET 1 OF 9 an *EQQQS mm kkkou uioguufi INVENTORS RALPH BERGER HOWARD SATTERLEE ATTORNEYS NEH 2 i]? 9 P'A'TENTEDMM 91972 am m m m QFm INVEN'IORS RALPH BERGER HOWARD SATTERLEE ATTORNEYS PATENTEDMAY 9:972 3.661.076

sum 6 or 9 FIG/la NORM/4L PATENTEDMY 91m $851,076

sum 7 OF 9 INPUT DATA 292 F l G I3 INVENTORS RALPH BERGER HOWARD SATTERLEE ATTORNEYS PATENTEDMAY 9 I972 1 D75 mmam9 INH'JN 'IORS RALPH BERGER HOWARD SATTERLEE PATENTEDMAY 91m (56 1 (.1753

INVENTORS f RALPH BERGER HOWARD SATTERLEE BY p ATTORNEYS BELT PRINTING APPARATUS FOR PRINTING LINE OF PRINT AT ONE TIME OTHER APPLICATIONS This is a continuation-in-part of our earlier application, Ser. No. 852,697, filed Aug. 25, 1969.

BACKGROUND 1. Field of the invention This invention relates generally to printing apparatus and more particularly to a medium speed printer capable of printing, by way of example, 60 to 100 lines per minute.

It is an object of the invention to provide an improved printing apparatus of the aforenoted type capable of reliably printing by the use of components which are readily and economically assembled and serviced.

Prior Art There are a number of printer constructions which employ displaceable belts cooperating with print hammers to effect a printing operation.

One such apparatus is known from U.S. Pat. No. 3,113,509 (VR. Simpson) which issued Dec. 14, I963. As will be seen from the description which follows hereinafter, the Simpson apparatus is distinguishable in that it employs a belt arrangement wherein the belt is aligned with the printed line and because it further employs a print hammer arrangement which is unlike that employed in accordance with the present invention.

U.S. Pat. No. 3,l64,084 (W. G. Paige), which issued Jan. 5, i965, likewise employs a plurality of belts to constitute a high speed belt printer, there being moreover employed an internal hammer arrangement. The apparatus disclosed by this patent is unlike that of the present invention in that it employs a plurality of print hammers and does not provide for bringing a multitude of characters to a single line of print to be operated upon simultaneously by a single hammer.

U.S. Pat. No. 3,l88,947 (W. G. Paige), which issued June l5, i965, similarly provides a plurality of belts, but is distin' guishable in that a plurality of print hammers is employed, each of which is associated with a relatively small number of belts. There is not shown in this patent an arrangement whereby an entire line of print is affected through the use of a single print hammer and consequently the arrangement of this patent is considerably more expensive and complicated than the arrangement of the present invention.

SUMMARY OF INVENTION In accordance with the invention there is provided a printing apparatus which comprises a sheet supply means for displacing a sheet of record medium such as paper through a printing station in a determinable direction to enable line-byline printing on said sheet in lines perpendicular to said direction and in a multitude of parallel columns aligned with said direction. A plurality of belts is employed with the belts being arranged in parallel to the aforesaid columns to which they correspond in number and in alignment. These belts preferably include like assortments of print characters serially distributed along corresponding lengths thereof.

in a first embodiment of the invention, the belts are driven by suitable driving means such that the aforesaid lengths are driven at least partly through the aforesaid printing station. A locating means is operatively associated with each of said belts to terminate movement thereof through the station so that a preselected print character is brought to a printing line at the printing station in each of the said columns.

In accordance with the invention a printing means is employed which displaces the thusly compiled line of print characters towards the sheet simultaneously to print an entire line at one time.

In further accordance with the invention, the means for driving the lengths bearing the characters through the printing station includes means for returning such lengths to a starting position from which the lengths can be driven in entirety through the print station in a succeeding cycle.

To provide for succeeding cycles there is provided apparatus for stepping the sheet line-by-line through the printing station in equal time increments. Also provided is a device to supply print ribbon between the sheet and print means.

As will be shown in greater detail hereinafter, the drive means and print means cooperatively include at least one drum for releasably driving the belts and a print hammer extending linearly across the aforesaid columns at the printing station. Cyclical means is provided to drive the aforesaid drums cyclically and there are actuating means responsive to this cyclical means to actuate the print hammer.

According to one feature of the invention, the cyclical means includes a pinion driven by a rack and in turn driving a sprocket which drives a chain which in turn drives a second sprocket coupled to the drum or drums driving the aforesaid belts. A crank is employed for driving the aforesaid rack and a cam is connected to and moves with the crankshaft and operates a toggle coupled to the print hammer.

Each of said belts may include two axially arranged sections, one of which inchldes the print characters and the other of which includes ratchet teeth by means of which the belts may be engaged for being halted with a proper character in position. This halting operation may be efiected, for example, by a sole operating stop which selectively engages one of the aforesaid teeth.

The sheet supply device employed in accordance with the invention may preferably include a ratchet and pawl assembly to supply driving power to a sprocket drive, the pawl being connected to the print hammer through intervening mechanisms so that the operation of these two elements is synchronized.

in accordance with one embodiment of the invention, the belts are driven by a plurality of drums with spaced parallel axes.

in accordance with another embodiment of the invention, a single drum is employed which is encircled by the aforesaid belts.

A further basic embodiment of the invention involves the use of means releasably engaging the belts and preventing the belts from moving through the printing station or with the associated driving means until released. in this embodiment of the invention a plurality of belts are held stationary and are selectively released to be driven by the associated driving means, the release of the belts being so timed that a line of print is compiled and the characters therein are moved concomitantly through the printing station wherein the printing operation is effected. in this embodiment of the invention the arrangement is preferably such that the belts encircle and frictionally engage a drum constituting the driving means.

in this latter embodiment of the invention the print means may include an anvil inside of the aforesaid drum and a print roller arranged externally of the drum in cooperating relationship with the anvil. The drum and roller in this case are driven with at least substantially equal peripheral speeds. The roller is, however, brought into cooperative relationship relative to the drum only once during every two rotations of the latter. This frees one cycle of the drum for bringing the belts back to an aligned starting position.

As a further feature of this latter embodiment of the invention, the belts can be provided with positioning lobes which cooperate with the anvil for accurate positioning of the characters. The belts will be provided, moreover, with stops engaged by locating means which both define the starting positions for the belts and release the belts for the selection of the various characters.

The invention will be more readily understood from the detailed description which follows hereinafter with reference to the accompanying drawing.

DRAWING FIG. 1 is a diagrammatic side view of a printing apparatus provided in accordance with one embodiment of the invention employing a plurality of driving drums;

FIG. 2(a) is a front view, on enlarged scale, of one of the driving drums;

FIG. 2(b) is an enlarged view of a portion of the aforesaid driving drum illustrating in cross-section printing belts supported on the said drum;

FIG. 3(a) is a side view of a printing belt employed in the invention in stretched-out condition;

FIG. 3(b) is atop view ofthe belt ofFIG. 3(a);

FIG. 4(a) is a diagrammatic illustration of the alignment of a plurality of belts when a printing operation is ready to be effected;

FIG. 4(b) is a diagrammatic view of the belts of FIG. 4(a) in their alignment at the startof a printing cycle;

FIG. 5 is a detailed view on enlarged scale illustrating how the ends of the belts are connected together in an endless loop;

FIG. 6 is a diagrammatic view on enlarged scale showing further details of the apparatus of FIG. 1 relative to the supply of paper;

FIG. 7 is a diagrammatic view illustrating the printing ribbon supply for the apparatus of FIG. 1;

FIG. 8 is a diagrammatic view of a clock or position indicator for use in the apparatus of FIG. 1;

FIG. 9 illustrates in diagrammatic form a plicable to the apparatus of FIG. 1;

FIG. 10 diagrammatically illustrates a second embodiment of the invention;

, FIGS. 1 1(a) and 11(b) diagrammatically illustrate the printing elements and arrangement for the apparatus of FIG. 10;

FIG. 12 diagrammatically illustrates a further embodiment of the invention;

FIG. 13 shows a section of FIG. 12 on enlarged scale;

FIG. I4 is a side view of an embodiment corresponding to FIG. I2; and

FIG. 15 is a top view ofthe apparatus in FIG. 14.

modification ap- DETAILED DESCRIPTION An exemplary purpose of the present invention is to provide a medium speed printer capable of printing, for example, 60 to I00 lines per minute. In a preferred machine, each line consists of, for example, 132 columns wherein the characters are spaced one-tenth of an inch apart. The characters, by way of example, occupy an area 0.093 X 0.063 inch in size.

In the particular machine under discussion with respect to a first embodiment of the invention, there are six lines of print per inch. EAch row or line of 132 columns is set up during a single cycle and at the end of the cycle the entire row or line of characters is printed at one time.

At the end of a given portion of a printing cycle and directly after the printing of a single line, the sheet of paper on which printing is being effected advances and provision may be made that the associated printing machine will advance at the same time.

The cycle then includes a reverse portion causing all columns to be reset to zero or starting position. As will be seen hereinafter, the term "reverse" is a generalized expression since the cycle can be zeroized by circular movement all in the same direction.

A printing operation consists of a plurality of repeated cycles in each of which a line of print is first assembled and then employed in a single hammer operation.

With reference to the details schematically shown in FIG. I, a printing apparatus in accordance with one embodiment of the invention comprises a plurality of drums 20, 22, 24 and 26 rotatable on shafts 28, 30, 32 and 34, the drums and shafts having spaced and parallel axes arranged at the four corners of a rectangle.

A plurality of belts, such as diagrammatically indicated at 38, encircles the aforesaid drums and are driven by these drums in a manner which will be indicated with greater particularity hereinafter.

On each of the above mentioned shafts is mounted a sprocket wheel. More particularly,.on shaft 28 is mounted a sprocket wheel 40, there being additionally provided sprocket wheels 42, 44 and 46 mounted on shafts 30, 32 and 34 respectively.

The aforesaid sprocket wheels are engaged and driven by a chain 48 arranged as an endless loop and in turn engaged by and driven by a sprocket wheel 50. Rotation of the sprocket wheel 50 drives the chain 48 thereby driving sprocket wheels 40, 42, 44 and 46, which in turn drive the drums 20, 22, 24 and 26 and thereby the belts 38.

From FIGS. 2(a) and 2(b) can be seen the construction of the above noted drums and the accommodation of the belts 38 thereon. Drum 20 is illustrated by way of example in FIG. 2(a). It is a one-piece cylindrical element provided with a plurality of annular grooves 52 separated by annular ribs 54. The drum may be, for example, two inches in diameter and the grooves 52 therein may be, for example, a total of 132 in number, the grooves being spaced by the ribs 54 at a distance, for example, of 0.100 inch. The drums may be made of any metal having suitable strength.

In FIG. 2(a) it is seen that the grooves 52 accommodate the belts 38 which lie flatly against the drum in said grooves. By way of example, in FIG. 2(b) are shown in section belts 38a, 38b and 380. These belts are, by way of example, 0.080 inch wide and 0.005 inch thick. They can be fabricated of metal or plastic and can be coined, etched or molded.

The construction of the aforesaid belts is indicated with greater particularity in FIGS. 3(a) and 3(b). Therein it can be seen that each such belt is formed of serially connected sections such as indicated by brackets 56 and 58. Section 56 is the print character including section. In this section will be included a plurality of characters 60 which may include, for example, the complete alphabet in capital letters, the complete alphabet in small letters, a series of numbers and whatever other signs and symbols are required to effect a normal printing operation. Generally, I 28 such characters are provided.

The belt section 58 includes a plurality of ratchet teeth 62. As will be shown, the ratchet teeth constitute a part of the arrangement by which the belts are brought to a halt for the appropriate positioning of the aforesaid characters. For this reason the ratchet teeth are identical in number to the number of characters 60. The pitch of the teeth and characters may, for example, be 0.166 inch and with I28 teeth and characters a total belt length of 42.6 inches will be involved.

FIGS. 4(a) and 4(b) show diagrammatically the use of belts of the aforesaid construction, it appearing that the belts 38 will be effectively staggered relative to each other to bring selected characters thereon to a print zone or area 64 for a printing operation. FIG. 4( b) shows that in the beginning of a printing cycle the belts 38, or more particularly, the character sections 56 thereon, are all in an initial starting position of alignment with one another wherefrom the belts are transported such that the sections 56 tend to move in entirety through the printing zone 64. In fact, and as will be shown in greater detail hereinafter, movement of the belts or belt sections is intercepted so that these sections end up in the staggered relationship appearing in FIG. 4(a) for purposes of a printing operation. The staggered relationship will, of course, be different for different printing cycles and printing operations so that a different line of print will be employed for each printing operation.

The belts are not employed in the stretched-out condition appearing in FIGS. 3 and 4. They are instead employed with their ends connected to form an endless loop. This appears in greater detail in FIG. 5 where can be seen a spring-like serpentine element 66 formed, for example, of beryllium copper or stainless steel, or the like, and connected to the ends 68 and 70 of a belt 38.

Where the belt 38 is fabricated of metal, the element 66 will be welded, braized or soldered to the ends thereof which are to be connected. If the belt 38 is fabricated of plastic, the element 66 can be molded into position.

ln any event, and with reference once again to FIG. 1, the belts 38 are supported in juxtaposed and parallel position corresponding to the columns which are to be printed and they are driven to move the characters past the printing zone by means of the aforenoted sprocket 50.

Sprocket wheel 50 is mounted on shaft 72, having mounted thereon a pinion gear 74. Pinion gear 74 is engaged and driven by a rack 76, rack 76 in turn being driven by crank 78.

The crank 78 in the illustrated embodiment of the invention under discussion is driven continuously in one direction so that the rack 76 is driven in opposite directions illustrated by arrow 80. This operates to drive the belts 38 first in one direction and then in the other direction for each complete cycle. The magnitude of movement which the belts 38 undertake is such that due to such movement all of the characters on each belt will be able to move past the printing station. In fact, and as has been noted hereinabove, this movement is intercepted so that a preselected character on each belt will be arrested in said printing station. The mechanism for accomplishing this is illustrated in the form of a solenoid 82 having as sociated therewith a stop 84. There is one such solenoid and stop for each belt and it is the function of each stop to engage one of the ratchet teeth on the associated belt as has been described hereinabove. The time at which the stop 84 will move into a position of interference is controlled by an electronic control 86, the details of which are not important to an understanding of this invention. However, it is to be understood that the electronic control 86 operates in conjunction with a belt position indicator 88 which may, for example, be controlled by an element mounted on the shaft 72 so that the electronic control 86 may select the character to be brought to the printing station for a particular belt 38 depending on the data supplied to the control 86 for purposes of controlling the printing operation.

The printing zone referred to hereinabove is a zone extending transversely of the columns of print and the direction of movement of the belts 38 and is, moreover, a zone which lies adjacent the print bar or hammer 90 and the print back up bar 92 between which elements pass all of the belts 38. There is also provided a print ribbon 94 by means of which ink is deposited upon the record medium or sheet 96 of paper upon which the printing operation is to be efi'ected.

Print hammer 90 is displaced by means of a toggle 98 including links 100 and 102. When these links are in rectilinear alignment, hammer 90 is displaced towards back up bar 92 and a printing operation is effected. When links 100 and 102 are angularly related as in the illustrated position thereof, the hammer 90 is withdrawn from the bar 92.

The relative attitude of links 100 and 102 is controlled by a linkage 104 pivotally connected at 106 to a link 108 supported on a pin 110. This linkage system is controlled by a cam 112 mounted for rotation with crank 78 on a shaft 1 14.

it will be appreciated from what has been stated hereinabove that rotation of crank 78 drives rack 76 and creates the driving force for the belts 38. It will now be appreciated further that such rotation actuates the link 104 and the toggle 98 and thus the print hammer 90. As a consequence thereof movement of the belts 38 and that of the hammer 90 are related. They are more particularly related so that movement of the hammer 90 follows the least possible time in which a different character can be moved through the printing zone so that a complete selection of characters is possible before the printing operation is effected. Specifically, this means that all of the characters on each of the belts 38 will have the opportunity if not previously intercepted to move to a position adjacent hammer 90 before this hammer will be motivated to effect a printing operation.

The hammer 90 is mounted on lever 114, in turn pivoted on pin 1 l6. This is employed in the control of paper supply as will soon be seen. As part of the paper supply apparatus there are provided sprockets 118 and 120 coupled to a chain 122. Also there are provided guides 124 and 126. The paper 96 in strip or sheet from passes between the guides and the aforesaid chain and is engaged by the sprockets I18 and and driven through the printing zone around the back up bar 92 and thence in the direction of discharge as indicated by arrow 128. The drive of the paper 96 is incremental and can best be appreciated from an examination of FIG. 6.

In FIG. 6 is shown the back up bar 92 in association with the print hammer 90 and ribbon 94, the hammer being mounted as aforesaid on the lever 114.

An arm contacm lever 114 and atop the arm 130 is pivotally mounted a pawl I32 supported on pin 134 and connected with arm 136. Pawl 132 engages a ratchet wheel 138 connected with sprocket 118 such that rotation of the ratchet wheel 138 rotates sprocket wheel 118 which is effective through chain 122 to drive sprocket wheel 120. It will also be seen that the pawl 132 is loaded by spring 140.

From what has been stated hereinabove, it will now be appreciated that movement of the hammer 90 in upward direction against back up bar 92 will carry arm 130 therealong and thus will carry along therewith pawl 132.

Upward movement of pawl [32 will be to the extent of one tooth on ratchet wheel 138 so that return movement of hammer 90 will cause pawl 132 to displace ratchet wheel 138 by an amount which is equal to one tooth, this in turn corresponding to the distance equal to that between successive lines of print on the sheet 96. As aforesaid, when there are six lines of print to the inch, this distance will be equal to 0.166 inch.

Also to be noted in FIG. 6 is the solenoid 142 actuated by coil 144 for the displacing of armature 146. Armature 146 cooperates with arm 136 to deactivate pawl 132 when it is desired that movement of the print hammer 90 not be accompanied by corresponding movement of the paper driven by sprockets 118 and 120.

The drive of the ribbon 94 appears more particularly in FIG. 7, wherein it is seen that the supply of the ribbon 94 includes a supply spool 148 and a take up spool 150. The paper is indicated again at 96 and the printing zone at 64. It is to be understood that the ribbon is purposefully passed at an angle relative to zone 64, since thereby a wider ribbon can be employed which is easier to control than a narrow ribbon. Movement of the ribbon 94 is provided by increment drive of a type corresponding to that employed for driving the paper.

FIG. 8 illustrates a clock or counter or position indicator 152 which can be mounted on the shaft 72 as aforesaid to provide infon'nation for the belt position indicator 88 of FIG. 1. The element 152 may be a sprocket wheel, a photoelectric device, a magnetic device or any other such device capable of generating pulses indicating movement of the wheel through the increments 154 corresponding to the various characters to be printed.

One such wheel may be associated with sprocket drive 50 to indicate the overall displacement which the drive tends to give to the belts 38. Pulses or other such signals derived from the element 152 will be counted in well known digital manner in the indicator 88 and this count will be compared in the control 86 also in well known manner with digital representations of the characters which are to be printed. Comparison when determined will be used to actuate the stops 84 to bring the corresponding belts to a halt. This terminating of the motion of the belts is possible due to the fact that the engagement between these beltsand the associated drums is frictional and any given belt can be brought to a halt with a selected character thereon in position at the printing zone even though the remaining belts may still be moving through the printing zone, as determined by the cycle of crank 78, hammer 90 will effect a printing operation and the belts 38 will be brought back to their initial position as determined by a stop (not shown) installed on each of the belts. The apparatus will then be ready for the next successive cycle which will be a repetition of what has been described above.

FIG. 9 illustrates a modification of which the ap aratus of FIG. 1 is susceptible. This modification involves simply the adjustable mounting of the drums 24 and 26 on adjustable bearing supports 156 and 158. The purpose of this adjustment is to provide for taking up slack in the belts 38 and also to align the characters to the print slot. This adjustment may require a take up of slack in the chain 48. Such requirement is met by the provision of a take up spool 160 mounted on a swingable arm 162.

A second embodiment of the invention appears in FIGS. 10 and 11, wherein it is seen that a single drum 164 can be employed instead of the plurality of drums discussed hereinabove. In this embodiment, belts 166 encircle the periphery of the drum and are selectively brought to a halt by means of a pivotal element 168 mounted for pivotal movement on pin 170 and controlled by solenoid 172. Movement of the paper 174 is diagrammatically illustrated as being controlled by drives 176 and 178, the paper moving around a back up 180 for the printing of successive lines.

FIGS. 11(a) and 11(b) diagrammatically illustrate how printing is effected, the back up 180 in this case being displaced by links 182, 184 and 186 to displace the back up toward and away from the drum and the print belt thereon in a manner generally like that which has been noted hereinabove.

In the embodiments of the invention described above, a line of print characters has been compiled by the selective arresting of each of the belts according to the character selected. According to the aspect of the invention to be described hereinbelow, the belts are associated with a driving means but are prevented from moving therewith until selectively released. This enables the compilation of a line of print characters which does not come to rest at the printing station but instead passes through the printing station for the momentary effecting of a printing operation.

in FIGS. 12 and 13 is illustrated a rotatable drum 200. The drum is driven through the intermediary of a gear 202 by means of a gear 204 coaxial with a toothed wheel 206 driven by a chain 208. This chain is in turn driven by a toothed wheel 210 coaxial and rotatable with a pulley 212 driven by a belt 214 in turn driven by a motor 216. A tension idler 218 is provided to cooperate with belt 208.

A chain 220 is driven by wheel 210 and in turn drives a toothed wheel 222 coaxial with and connected to a print roller 224 provided with a lobe 226. Wheel 222 and roller 224 are supported on a frame 228 which is pivotable about shaft 230 on which wheel 210 and pulley 212 are supported. A tension idler 232 is provided in cooperating relationship with belt 220.

Within drum 200 is mounted a guide 234 within which is slideable an anvil 236 for radial displacement within said guide. In circumferential grooves provided on the surface of drum 200 are located a plurality of belts 238 on which print characters 240 are located. The insides of the various belts are preferably provided with positioning lobes 242 cooperating with positioning groove 244 on the end of the anvil. The purpose of these lobes and the grooves at the end of the anvil is to provide for the precise locating of the print characters as they are brought in a compiled line to the printing station.

A gear 246 is mounted for rotation on a shalt 248 supported by frame 228 and is rotated by gear teeth provided on shaft 230. Coaxial with gear 246 is a cam 250 provided with a peripheral depression 252, the purpose of which will be hereinafter indicated. It should be noted that the gear and pulley arrangement, however, is such that the cam 250 rotates one complete cycle for each two complete cycles of rotation of the drum 200.

Mounted on frame 228 is a pivot pin 254 supporting an arm 256 on which is mounted cam follower 258. At the opposite extremity of arm 256 is mounted a pivot pin 260 to which is connected a link 262. Link 262 is connected to a linkage arrangement consisting of links 264 and 266 pivotally connected by pin 268, the link 264 being pivotable about a fixed pivot 270. Link 266 is pivotally connected to frame 228 by pin 272. It can be seen in FIG. 12 that the linkage has extended and retracted conditions in which the frame 228 is respectively displaced either toward or away from drum 200 whereby print roller 224 assumes the operative position cooperating with anvil 236 or the withdrawn position 224a in which no printing operation can be effected.

It will be noted that arm 256 is provided with an abutment 276 adapted for cooperation with armature 278 of solenoid 280. When armature 278 is attracted towards the solenoid coil, no engagement between abutment 276 and armature 278 is possible. When the armature is in the extended position, abutment 276 comes to rest against armature 278 and displacement of print roller 274 towards the drum 200 is not possible.

Each belt is provided with a stop 281 in connection with which there is provided a corresponding latch 282, spring loaded, for example, by spring 284. The latch can be displaced by a release control 286 in turn controlled by a comparator 288, the inputs to which are provided by a scanner 290 and an input data source 292.

The scanner 290 operates, for example, to read a magnetized code or the like provided on gear 202 or some part associated therewith. Such magnetic identification is well known in the computer art and is not the specific subject of the present invention. Alternatively, photoelectric pick ups or mechanical pick ups can be substituted. in any event. the scanner 290 identifies the particular rotational position of the drum 200. This information is fed into the electronic comparator 288 which compares the rotational position of the drum with an electronically coded signal identifying the characters to be printed in each column of the line of print to be compiled. The latch 282, which up to this point has been bearing against the corresponding stop 28] releases the same so that the belt which has heretofore been prevented from moving with the drum 200 is released at the precise time which will enable the selected character thereon to be brought adjacent the anvil 236 when the compiled line of print is to be impressed on a sheet of paper P or the like with the use of a printing ribbon R or some other equivalent source of ink.

Since the belts are selectively released for movement with drum 200, it follows as a consequence thereof that the print characters need not be stopped at the printing station, but will move directly therethrough. For this purpose the rotational speed of the print roller 224 is related to that of the drum 200 to make the speed of the lobe 226 correspond to that of the characters moving through the printing station. This provision will avoid blurring.

[t is then necessary to bring all of the belts to a position of rest from whence the next printing cycle can proceed. For this reason, the drum and cam have an idling cycle during which the print roller 224 is withdrawn and during this cycle all of the stops 281 come to bear against the corresponding latches 282 whereupon a starting condition is brought about.

An advantage of the aforegoing structure is that mechanical provision for paper feed can be dispensed with. The paper is squeezed between the anvil mounted on the rotating drum 200 and the lobe 226 on the rotating print roller 224. The paper being thus squeezed is automatically fed step by step. in the printing operation the engaging of groove 244 on the end of anvil 236 with locating lobes 242 precisely positions the belts at the instant of printing.

By way of example, the drive motor for the above construction can be 1/20 h.p. in size. This is adequate to account for production variations in belt slip, friction and so forth. in a preferred embodiment of the invention, a shaft 230 rotates at a speed of 480 rpm. The motor speed may be, for example, from 1,700 to 1,800 rpm. From the shaft 230, the drive proceeds to three essential places. The 480 rpm speed is trans ferred to the print roller 224 and to the gear 204. Drum 200 rotates at a speed of rpm. The dimensions of the print roller 224 and drum 200 are such that the peripheral speeds of these two elements are the same.

FIGS. 14 and 15 illustrate a variation of the last described embodiment and these figures are intended specifically to show the locating or releasing mechanism in greater detail. In these figures are illustrated a drum 300 provided with grooves 302 in which are located belts 304. Each belt is provided with a stop which is engaged by a latch 306 pivotable on pin 308 in a bracket 310. Each latch is loaded by a spring 312. To each latch is connected a strip 314, at the end of which is mounted a twisted strip 316 mounted on a reed 318. To this reed is connected an armature element 320 of a solenoid 322, the operation of which causes the reed 318 to bend thereby displacing strip 314 in the direction indicated by arrow 324.

Additional solenoids are indicated at 326, 328 and 330, there being one such solenoid for each belt, each of which supports the entire group of characters from which selection is to be made.

The drum 300 is driven by a motor 332 in a manner consistent with the operation which has been described hereinabove.

Relative to the aspect of the invention which appears in FIGS. 12-45, it is seen that a driven drum has a frictional engagement with a plurality of belts which are normally prevented from moving with the drum, but which are selectively released to be driven by the drum through a printing station in a manner such that a compiled line of print characters simultaneously passes through the printing station. At the printing station a printing operation is effected by the use of a print roller and an anvil, these elements cooperating in such a manner as to effect automatic paper feed. It will be further noted that the drum is given a sequence of operations whereby print cycles are separated by idle cycles during which the belts are returned to starting positions.

What is claimed is:

1. Printing apparatus for printing on a sheet of record medium adapted for being displaced through a printing station in a determinable direction to enable a line-by-line printing on said sheet in lines perpendicular to said direction and in a multitude of parallel columns aligned with said direction, a plurality of belts parallel to said columns and corresponding in number thereto, said belts including like assortments of print characters serially distributed along corresponding lengths of said belts, drive means adapted for driving each of said lengths through said station, locating means operatively associated with said belts to prevent movement thereof through said station but to release the belts selectively so that preselected print characters are brought simultaneously to a printing line at said station in each of said columns to compile a line of print characters, and print means to displace the thusly compiled line of print characters and said sheet together to print an entire line all at one time, said drive means including a drum adapted for driving said belts and said locating means including means releasably engaging the belts to prevent the latter from moving with the drum until respectively and selectively released whereupon the belts move with the drum and the preselected print characters pass through said printing station simultaneously.

2. Printing apparatus as claimed in claim 14, wherein said locating means includes means controlling the release of the respective belts to enable said compiled line of print characters to reach said print line simultaneously.

3. Printing apparatus as claimed in claim 2, wherein said belts encircle and frictionally engage said drum.

4. Printing apparatus as claimed in claim 2, wherein said print means includes anvil means inside said drum and a print roller external of said drum in cooperating relationship with said anvil means, said apparatus further including means to drive the drum and roller with at least substantially equal peripheral speeds.

5. Printing apparatus as claimed in claim 4 comprising means to displace said roller to an inoperative position spaced from said drum and means for selectively retaining the roller in said operative position.

6. Printing apparatus as claimed in claim 4 comprising a lobe on said roller to cooperate with said anvil means.

7. Printing apparatus as claimed in claim 4, wherein said belts include positioning lobes, said anvil means having a shape to accommodate the positioning lobes for accurately positioning the characters. I I I I I 8. Printing apparatus as claimed lIl claim 2, comprising stops on said belts, said locating means including latches cor responding to said stops and solenoids to operate said latches.

9. Printing apparatus as claimed in claim 8, comprising parallel strips connecting said latches to said solenoids, said solenoids including operating members engaging the strips and reeds supporting the operating members for displacement.

10. Printing apparatus as claimed in claim 4, comprising means for displacing the print roller to an inoperative position spaced from said drum and for bringing the print roller into cooperating relationship with said anvil means during alternate rotations of the drum between which the belts are reset to starting positions by said locating means. 

1. Printing apparatus for printing on a sheet of record medium adapted for being displaced through a printing station in a determinable direction to enable a line-by-line printing on said sheet in lines perpendicular to said direction and in a multitude of parallel columns aligned with said direction, a plurality of belts parallel to said columns and corresponding in number thereto, said belts including like assortments of print characters serially distributed along corresponding lengths of said belts, drive means adapted for driving each of said lengths through said station, locating means operatively associated with said belts to prevent movement thereof through said station but to release the belts selectively so that preselected print characters are brought simultaneously to a printing line at said station in each of said columns to compile a line of print characters, and print means to displace the thusly compiled line of print characters and said sheet together to print an entire line all at one time, said drive means including a drum adapted for driving said belts and said locating means including means releasably engaging the belts to prevent the latter from moving with the drum until respectively and selectively released whereupon the belts move with the drum and the preselected print characters pass through said printing station simultaneously.
 2. Printing apparatus as claimed in claim 14, wherein said locating means includes means controlling the release of the respective belts to enable said compiled line of print characters to reach said print line simultaneously.
 3. Printing apparatus as claimed in claim 2, wherein said belts encircle and frictionally engage said drum.
 4. Printing apparatus as claimed in claim 2, wherein said print means includes anvil means inside said drum and a print roller external of said drum in cooperating relationship with said anvil means, said apparatus further including means to drive the drum and roller with at least substantially equal peripheral speeds.
 5. Printing apparatus as claimed in claim 4 comprising means to displace said roller to an inoperative position spaced from said drum and means for selectively retaining the roller in said operative position.
 6. Printing apparatus as claimed in claim 4 comprising a lobe on said roller to cooperate with said anvil means.
 7. Printing apparatus as claimed in claim 4, wherein said belts include positioning lobes, said anvil means having a shape to accommodate the positioning lobes for accurately positioning the characters.
 8. Printing apparatus as claimed in claim 2, comprising stops on said belts, said locating means including latches corresponding to said stops and solenoids to operate said latches.
 9. Printing apparatus as claimed in claim 8, comprising parallel strips connecting said latches to said solenoids, said solenoids including operating members engaging the strips and reeds supporting the operating members for displacement.
 10. Printing apparatus as claimed in claim 4, comprising means for displacing the print roller to an inoperative position spaced from said drum and for bringing the print roller into cooperating relationship with said anvil means during alternate rotations of the drum between which the belts are reset to starting positions by said locating means. 